JP2007126888A - Screen and method of connecting the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a screen which can be connected to another one without welding work, contributes to drastic reduction of costs necessary for screen connection and to prevention of loss of a screen effective length, and to provide a method of connecting the screens together. <P>SOLUTION: The screen 10 is formed of: a rod-shaped member arrangement section 12 in which a plurality of rod-shaped members 11 are circumferentially arranged in a manner almost forming a cylindrical shape at predetermined intervals away from each other; and annular section 15 which is obtained by winding a wire member 13 on a radially external side of the rod-shaped member arrangement section 12 so as to be fixed to the rod-shaped members, in a manner securing a predetermined interval 14b in a longitudinal direction of the rod-shaped members. Herein at least at one of longitudinal ends of the rod-shaped member arrangement section 12, screw groove forming sections 12a about an axis of the rod-shaped member arrangement section as the center, are formed in a radially internal surface of the rod-shaped member arrangement section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a screen used as an internal element for wells and various plants and devices, and a connection structure thereof.

  Conventionally, for example, in order to collect groundwater, a pipe-like screen formed of stainless steel or the like is embedded in the formation. In this screen, a plurality of rod-shaped members called rods are arranged in the circumferential direction at equal intervals, and a wire is spirally wound around the outer circumferential surface of these rod-shaped members at a constant pitch in the longitudinal direction of the rod-shaped members. They are integrated by electrical resistance welding at the intersection of the wire and the wire, and are formed into a pipe shape as a whole. In other words, there are gaps formed between the wires in the circumferential direction and the longitudinal direction on the circumferential surface of the screen, and fluid flows into the screen tube by the gaps, or the fluid in the screen tube flows to the outside. (See, for example, Patent Document 1).

  Therefore, for example, when collecting groundwater, a hole for inserting a screen from the ground surface by an excavator or the like is formed, so that the gap formed on the circumferential surface of the screen is located at the formation position where the groundwater exists. A screen is installed in the hole, and groundwater is collected by flowing into the inner diameter side of the screen.

  Usually, since groundwater exists deep in the formation, the screens are inserted into the holes while being connected one by one. For example, as shown in FIG. 5A, this connection is performed by welding a connecting piece portion 201 provided with a female screw portion at an axial end portion of one screen 101 and an axial direction of the other screen 102. A welded piece of connecting piece 202 having a male threaded portion at the end is prepared. As shown in FIG. 5 (b), a female threaded part of connecting piece 201 and a male screw of connecting piece part 202 are prepared. Both screens are connected by screwing the part together. Here, as shown in FIG. 6, the screen 101 is composed of the rod 101a and the wire 101b as described above. The welding of the connecting piece 201 to the screen 101 is the longitudinal end of the rod 101a of the screen 101. And the axial end of the connecting piece 201 are welded from the inner diameter side. That is, when welding is performed from the outer diameter side, the connecting piece 201 and the wire 101b are welded. However, since the wire 101b is welded only at the intersection with the rod 101a, only the welding portion at these intersections is used. The connection piece 201 is connected and held. In such a connection, since the strength is not sufficient as the strength for connecting the connecting piece portions 201, the connecting piece portions 201 are welded to the plurality of rods 101a at the welding points 300 on the inner diameter side. Further, when it is difficult to weld from the inner diameter side of the rod 101 a and the connecting piece 201 due to the relationship between the aperture of the screen 101 and the axial length of the connecting piece 201, the short ring member 210 is first attached to the screen 101. The ring member 210 and the connecting piece 201 are connected by welding at the welding location 301 from the outer diameter side (FIG. 7). Although not shown, the same applies to the welding of the ring member and the connecting piece 202 to the screen 102.

The screen 101 and the screen 102 to which the connecting piece portions 201 and 202 are welded are connected by screwing the male screw portion of the connecting piece portion 201 and the female screw portion of the connecting piece portion 202.
JP-A-6-272285

  However, the operation of welding the connecting pieces 201 and 202 to connect the screens 101 and 102 as described above is welding from the inner diameter side of the screen, and it is necessary to weld each rod 101a and the connecting pieces 201 and 202. Therefore, it is very troublesome and requires a lot of work time. For connection, different connection piece parts such as a connection piece part 201 having a female screw part and a connection piece part 202 having a male screw part are separately required, and a ring member 210 is separately prepared as necessary. From the fact that it is necessary to do this, the parts cost and the work cost in the connecting part increase, and the connecting construction cost of the screen has to be increased.

  Moreover, in the conventional connection method, since the external thread part or internal thread part formed in connection piece part 201,202 is located between the screens 101 and 102, a connection part necessarily becomes long in a screen longitudinal direction. When this connecting portion becomes longer, the ratio of the gap formed on the circumferential surface of the screen becomes smaller than the length of the screen. That is, there is a problem that the effective screen length is reduced.

  The present invention has been made in view of the above-described problems, eliminates the need for welding work for screen connection, can significantly reduce the cost of screen connection work, and can further reduce the loss of screen effective length. An object of the present invention is to provide a screen and a connecting structure thereof.

  In order to solve the above-mentioned problems, a screen according to the present invention includes a rod-shaped member arrangement portion in which a plurality of rod-shaped members are arranged in a circumferential direction so as to form a substantially cylindrical shape with a predetermined interval therebetween, and the rod-shaped member. In the screen, comprising: an annular portion that is wound around the radially outer side of the array portion so that the wire member has a predetermined interval in the longitudinal direction of the rod-shaped member and is fixed to the rod-shaped member. At the longitudinal end of the member arrangement portion, a screw groove constituting portion centering on the axis of the rod-like member arrangement portion is formed on the radially inner side of the rod-like member arrangement portion.

  According to the screen described above, since the thread groove constituting portion centering on the axis of the rod-shaped member arrangement portion is provided at the end of the screen, the screen can be connected using the thread groove constituting portion. That is, the grooves provided on the inner side in the radial direction of each rod-shaped member form a series of intermittent spiral grooves (screw grooves) having a substantially female thread shape as a whole when the rod-shaped member arrangement portion is formed. Therefore, since the screen can be connected by screwing a connecting member having a male screw part into the screw groove constituting part formed in this way, troublesome work such as welding can be eliminated.

  In order to solve the above problems, a screen connection structure according to the present invention is a screen connection structure including the screen of the present invention and a connection member for connecting the screen. Male screw portions are provided at both ends, the male screw portion of one end of the connecting member and the screw groove constituting portion of the first screen are screwed together, and the male screw portion of the other end of the connecting member and the second screen It is characterized by being configured by screwing the thread groove constituting portion.

  According to the connecting structure of the screen, the screen can be connected only by screwing the screen to the connecting member. Therefore, the connecting work by welding which was conventionally required becomes unnecessary, and the cost of screen connecting work can be reduced. Further, since the male screw portion formed on the connecting member is located on the inner diameter side of the screen end, the connecting portion is not longer than necessary with respect to the screen length, and the connecting portion itself can be formed small. Accordingly, the screens can be connected while suppressing the loss of the effective screen length.

  The connecting member can be made of either metal or resin. However, when the screens connected to both ends of the connecting member are made of different metals, the connecting member is made of resin. This is preferable in that potential difference corrosion can be prevented. For example, since the screen and the tubular casing embedded in the formation other than a part of the groundwater are usually made of different metals, when connecting them, it is easy to use a connecting member made of resin. Potential difference corrosion due to dissimilar metal bonding can be prevented.

  According to the screen of the present invention and the connection structure thereof, the screen can be easily connected without a welding operation. In addition, since the connecting portion can be reduced in the length direction of the screen, the screen can be connected while suppressing the loss of the effective screen length.

  Preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an example in which a screen 10 of the present invention is applied for a well, and is a schematic side view showing a state in which the screen 10 is connected to another screen 10 or a casing 30 and embedded in a formation. FIG. 2 is a perspective view of the screen 10 of the present invention.

  As shown in FIG. 1, the screen 10 is disposed in the formation g while being connected to another screen 10 or a casing 30 via a connecting member 20. Here, w indicates a formation in which groundwater exists in the formation g, and is hereinafter referred to as a groundwater layer w.

  As shown in FIG. 2, the screen 10 is composed of a rod-shaped member arrangement portion 12 composed of a plurality of metal rods 11 extending in the longitudinal direction and an annular portion 15 composed of a metal wire member 13. Has been. In the present embodiment, the rod 11 and the wire member 13 are made of metal, but the present invention is not limited to this.

  The rod-shaped member arrangement portion 12 is configured such that a plurality of rods 11 are arranged in a substantially circular shape at substantially equal intervals, and form a substantially cylindrical shape as a whole.

  As shown in FIGS. 2 and 3, the rod 11 is a rod-like member that extends linearly. In the embodiment shown in FIG. 2, a case where the cross-sectional shape is a triangle is shown as an example, but any shape such as a circle, a piece, or a square can be used, and the shape is not limited to a triangle.

  The rod 11 is formed on an inner surface 11c (see FIG. 3) that forms the radially inner side surface of the rod-shaped member arrangement portion 12 so as to cross the longitudinal direction of the rod 11, and is predetermined in the longitudinal direction. A plurality of grooves 11b are arranged at a pitch. These grooves 11b form a series of intermittent spiral grooves as a whole on the radially inner side when the rod-shaped member arrangement portion 12 is formed. That is, when each rod 11 forms the rod-shaped member arrangement portion 12, a screw groove constituting portion 12a corresponding to a female screw having the axial center of the rod-like member arrangement portion 12 as the center is constituted.

  The annular portion 15 is configured by winding a wire member 13. That is, as shown in FIGS. 2 and 3, the wire member 13 is arranged in the circumferential direction of the rod-shaped member arrangement portion 12 so as to contact the outer surface of the rod 11 forming the radially outer surface of the rod-like member arrangement portion 12. It is wound at a predetermined pitch. Then, in a state where the adjacent wire members 13 have a predetermined gap 14b, the intersection 11a where the outer surface of the rod 11 and the wire member 13 abut is welded by electric resistance welding, and the flow of fluid through the gap 14b Outflow is possible. Specifically, for example, as shown in FIG. 1, when the gap 14b is positioned in the groundwater layer w, groundwater flows from the groundwater layer w through the gap 14b. That is, the range in which the gap 14b is provided is the effective screen length.

  Further, as shown in FIG. 4, the connecting member 20 is a hollow or solid cylindrical member formed of a metal such as stainless steel, and includes a trunk portion 21 at the center in the axial direction thereof. Both end portions are provided with a first male screw portion 22a and a second male screw portion 22b. Therefore, for example, if the first male screw portion 22a of the connecting member 20 is inserted into the longitudinal end portion of the screen 10 and rotated in the direction in which the screw is fastened, the thread of the first male screw portion 22a is intermittently generated. The screen 10 and the connecting member 20 are finally connected by sequentially screwing into the thread groove constituting portion 12a at the end of the screen 10 provided.

  The casing 30 is a pipe-shaped member made of iron or resin, and is disposed at a place other than the groundwater layer w. The casing 30 is provided with a thread groove at the end in the longitudinal direction thereof to be screwed with the male threaded portions 22 a and 22 b of the connecting member 20.

  When the screen 10 and the connecting member 20 configured as described above are connected, as shown in FIG. 4A, the screen 10 to be connected is disposed at the end of the connecting member 20, and one screen 10 is connected. The first male screw portion 22a of the connecting member 20 is screwed into and fixed to the screw groove constituting portion 12a (not shown) (FIG. 4B). Next, the second male screw portion 22b of the connecting member 20 is screwed and fixed to the screw groove constituting portion 12a (not shown) of the other screen 10 (FIG. 4C).

  Also, in the connection between the screen 10 and the casing 30, the male screw portions 22 a and 22 b of the connecting member 20 are screwed into the screw grooves provided in the casing 30 in the same manner as described above. can do.

  Therefore, in the screen of the present invention and the connecting structure thereof, the screens 10 or the screen 10 and the casing 30 can be connected to each other without performing the work by welding the rods 11 and the connecting members, which has been conventionally required. This eliminates the need for welding work and reduces the cost of connecting work.

  Furthermore, since the present invention does not involve a welding operation, the gap 14b provided in the screen 10 can be connected without being affected by heat. In other words, conventionally, since the welding work is involved, the gap 14b near the welding location is affected by the heat of the welding, and the accuracy may be affected by thermal expansion or the like. Therefore, the connection can be made while maintaining the accuracy of the gap 14b.

  Moreover, since the thread groove structure part connected with the connection member 20 was provided in the internal diameter side of the screen 10, the length of the connection part of a screen longitudinal direction can be shortened, and the loss of screen effective length can be suppressed.

  Furthermore, in the past, it was necessary to prepare two types of connecting pieces, but in the connecting structure of the present invention, the screen 10 can be connected by one type of connecting member 20. Therefore, it is possible to reduce the cost of parts for connecting.

  Further, the screen 10 of the present invention is not limited to wells as shown in the above embodiment, but can also be applied as an internal element used in a plant or the like. In this case, conventionally, the screen and other counterpart members are used. In some cases, the screen or the connecting piece portion is provided with a flange at the connecting portion and fastened with a bolt or the like. Space can be saved in the portion, and unnecessary costs such as providing a flange can be reduced.

  Moreover, although the case where the connecting member 20 is made of metal has been described in the above embodiment, when the screen 10 and the casing 30 are formed of different materials and connected, or the screens 10 formed of different materials are connected to each other. In some cases, the connecting member 20 may be made of resin. In this case, potential difference corrosion due to joining of dissimilar metals is prevented, and progress of corrosion can be suppressed. The material of the connecting member 20 is not limited to these, and any material that can be threaded, such as hard rubber or ceramics, can be used.

  Moreover, although the said embodiment demonstrated the case where the screen 10 was formed with the metal rod 11 and the wire member 13, you may form these with the resin rod 11 and the wire member 13. FIG. In this case, the screen 10 resistant to corrosive environments can be obtained.

It is a schematic side view which shows the state by which the screen of this invention was embedded in the formation. It is a perspective view of the screen of this invention. It is sectional drawing in the edge part of the screen of this invention. It is a figure which shows the aspect which connects a screen and a connection member, (a) is a figure which shows the state before connection, (b) is a figure which shows the state which connected one screen, (c) is a figure. It is a figure which shows the state after completion of a connection. It is a figure which shows the aspect of the connection of the conventional screen, (a) is a figure which shows the state before connection, (b) is a figure which shows the middle step of connection. It is sectional drawing which shows the connection state of the connection piece part of the conventional screen. It is sectional drawing which shows the other connection state of the connection piece part of the conventional screen.

Explanation of symbols

10 Screen 11 Rod (bar-shaped member)
11b Groove 12 Bar-shaped member arrangement part 12a Thread groove constituting part 13 Wire member 14b Gap 15 Annular part

Claims (3)

A plurality of rod-shaped members arranged in the circumferential direction so as to form a substantially cylindrical shape with a predetermined interval from each other;
An annular portion that is wound around the radially outer side of the rod-shaped member array portion so that the wire member has a predetermined interval in the longitudinal direction of the rod-shaped member and is fixed to the rod-shaped member;
In the screen with
At least one of the rod-shaped member arrangement portions has a longitudinal end portion formed with a thread groove forming portion centered on the axis of the rod-shaped member arrangement portion on the radially inner side of the rod-shaped member arrangement portion. Screen to play. In the screen connection structure comprising the screen according to claim 1 and a connection member for connecting the screen,
Male screw portions are provided at both ends of the connecting member, the male screw portion of one end of the connecting member and the screw groove constituting portion of the first screen are screwed together, and the male screw portion of the other end of the connecting member is 2. A connecting structure for a screen, which is configured by screwing a screw groove constituting portion of the screen of 2.   The screen connection structure according to claim 2, wherein the connection member is made of resin.

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